Mobile device and optical imaging lens thereof

ABSTRACT

An optical imaging lens includes six lens elements disposed sequentially from an object side to an image side. The image-side surface of the first lens element comprises a concave portion in a vicinity of an optical axis. The third lens element has positive refracting power. The fourth lens element has positive refracting power. The image-side surface of the fifth lens element comprises a convex portion in a vicinity of the optical axis. The optical imaging lens as a whole has only the six lens elements having refractive power.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/795,801, filed on Jul. 9, 2015, which is a continuation of U.S.patent application Ser. No. 13/963,717, filed on Aug. 9, 2013, now U.S.Pat. No. 9,097,876, which claims priority to Chinese Patent ApplicationNo. 201310159899.7, filed on May 3, 2013, the disclosures of which arehereby incorporated by reference in their entirety for all purposes.

TECHNICAL FIELD

The present invention relates to a mobile device and an optical imaginglens thereof, and particularly, relates to a mobile device applying anoptical imaging lens having six lens elements and an optical imaginglens thereof.

BACKGROUND

The ever-increasing demand for smaller sized mobile devices, such ascell phones, digital cameras, etc. has correspondingly triggered agrowing need for smaller sized photography modules contained therein.Size reductions may be contributed from various aspects of the mobiledevices, which includes not only the charge coupled device (CCD) and thecomplementary metal-oxide semiconductor (CMOS), but also the opticalimaging lens mounted therein. When reducing the size of the opticalimaging lens, however, achieving good optical characteristics becomes achallenging problem.

The conventional optical imaging lenses generally have six lenselements. Since less number of the lens elements, the total length ofthe conventional optical imaging lenses could be limited to a certainlength range. However, the ever-increasing demand for high standardproductions, such as 12 million pixels smart phones or digital cameras,etc. has correspondingly triggered a growing need for high resolutionand high quality. Therefore, there is needed to develop an opticalimaging lens having six lens elements for high specification products.

SUMMARY

An object of the present invention is to provide a mobile device and anoptical imaging lens thereof. With controlling the convex or concaveshape of the surfaces of the lens elements, the length of the opticalimaging lens is shortened and meanwhile the good optical characters,such as high resolution, are sustained.

In an exemplary embodiment, an optical imaging lens, sequentially froman object side to an image side, comprises first, second, third, fourth,fifth and sixth lens elements, each of said lens elements having anobject-side surface facing toward the object side and an image-sidesurface facing toward the image side, in which the object-side surfaceof the first lens element comprises a convex portion in a vicinity ofthe optical axis; the image-side surface of the second lens elementcomprises a concave portion in a vicinity of a periphery of the secondlens element; the image-side surface of the third lens element comprisesa convex portion in a vicinity of a periphery of the third lens element;the image-side surface of the fourth lens element comprises a convexportion in a vicinity of the optical axis; the image-side surface of thefifth lens element comprises a convex portion in a vicinity of aperiphery of the fifth lens element; and the image-side surface of thesixth lens element comprises a concave portion in a vicinity of theoptical axis and a convex portion in a vicinity of a periphery of thesixth lens element; the optical imaging lens as a whole having only thesix lens elements having refractive power. Accordingly, with controllingthe convex or concave shape of the surfaces of these lens elements, thelength of the optical imaging lens is shortened efficiently andmeanwhile the aberration is eliminated for sustaining good opticalcharacters.

In an exemplary embodiment, the object-side surface of the sixth lenselement may be designed to have a concave portion in a vicinity of theoptical axis and a convex portion in a vicinity of a periphery of thesixth lens element, the image-side surface of the third lens element maybe designed to have a convex portion in a vicinity of the optical axis,and the image-side surface of the fourth lens element may be designed tohave a convex portion in a vicinity of a periphery of the fourth lenselement. Accordingly, with controlling the convex or concave shape ofthe surfaces of these lens elements, the length of the optical imaginglens is shortened efficiently and meanwhile the aberration is eliminatedfor sustaining good optical characters.

In another exemplary embodiment, some equation(s), such as thoserelating to the ratio among parameters could be taken intoconsideration. For example, an effective focal length of the opticalimaging lens, EFL, and a central thickness of the third lens elementalong the optical axis, CT3, could be controlled to satisfy the equationas follows:

$\begin{matrix}{6.00 \leq {\frac{EFL}{{CT}\; 3}.}} & {{Equation}\mspace{14mu}(1)}\end{matrix}$

In another exemplary embodiment, a distance from the object-side surfaceof the first lens element to the image-side surface of the sixth lenselement, TL, and a central thickness of the sixth lens element along theoptical axis, CT6, could be controlled to satisfy the equation asfollows:

$\begin{matrix}{7.60 \leq {\frac{TL}{{CT}\; 6}.}} & {{Equation}\mspace{14mu}(2)}\end{matrix}$

In another exemplary embodiment, an air gap between the fifth lenselement and the sixth lens element, AC56, a central thickness of thesecond lens element along the optical axis, CT2, and EFL could becontrolled to satisfy the equation as follows:

$\begin{matrix}{5.00 \leq {\frac{EFL}{{{CT}\; 2} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(3)}\end{matrix}$

In another exemplary embodiment, an air gap between the second lenselement and the third lens element, AC23, an air gap between the thirdlens element and the fourth lens element, AC34, and CT3 could becontrolled to satisfy the equation as follows:

$\begin{matrix}{2.30 \leq {\frac{{{AC}\; 23} + {{CT}\; 3} + {{AC}\; 34}}{{CT}\; 3}.}} & {{Equation}\mspace{14mu}(4)}\end{matrix}$

In another exemplary embodiment, a sum of all air gaps from the firstlens element to the sixth lens element along the optical axis, AAG,AC23, and AC34 could be controlled to satisfy the equation as follows:

$\begin{matrix}{\frac{AAG}{{{AC}\; 23} + {{AC}\; 34}} \leq {1.81.}} & {{Equation}\mspace{14mu}(5)}\end{matrix}$

In another exemplary embodiment, an air gap between the first lenselement and the second lens element, AC12, an air gap between the fourthlens element and the fifth lens element, AC45, AC34 and AC56 could becontrolled to satisfy the equation as follows:

$\begin{matrix}{1.20 \leq {\frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(6)}\end{matrix}$

In another exemplary embodiment, a central thickness of the fourth lenselement along the optical axis, CT4, a central thickness of the fifthlens element along the optical axis, CT5, and EFL could be controlled tosatisfy the equation as follows:

$\begin{matrix}{\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}} \leq {5.40.}} & {{Equation}\mspace{14mu}(7)}\end{matrix}$

In another exemplary embodiment, the sum of the thickness of all sixlens elements along the optical axis, ALT, and a central thickness ofthe sixth lens element along the optical axis, CT6, could be controlledto satisfy the equation as follows:

$\begin{matrix}{5.50 \leq {\frac{ALT}{{CT}\; 6}.}} & {{Equation}\mspace{14mu}(8)}\end{matrix}$

In another exemplary embodiment, an air gap between the fifth lenselement and the sixth lens element, AC56, CT6 and EFL could becontrolled to satisfy the equation as follows:

$\begin{matrix}{6.30 \leq {\frac{EFL}{{{CT}\; 6} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(9)}\end{matrix}$

In another exemplary embodiment, a central thickness of the third lenselement, CT3, and EFL could be controlled to satisfy the equation asfollows:

$\begin{matrix}{8.30 \leq {\frac{EFL}{{CT}\; 3}.}} & {{Equation}\mspace{14mu}\left( 1^{\prime} \right)}\end{matrix}$

In another exemplary embodiment, a central thickness of the second lenselement, CT2, a central thickness of the fourth lens element, CT4, and acentral thickness of the fifth lens element, CT5, could be controlled tosatisfy the equation as follows:

$\begin{matrix}{2.80 \leq {\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2}.}} & {{Equation}\mspace{14mu}(10)}\end{matrix}$

In another exemplary embodiment, a central thickness of the second lenselement, CT2, an air gap between the fifth lens element and the sixthlens element, AC56, and TL could be controlled to satisfy the equationas follows:

$\begin{matrix}{5.50 \leq {\frac{TL}{{{CT}\; 2} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(11)}\end{matrix}$

Aforesaid exemplary embodiments are not limited and could be selectivelyincorporated in other embodiments described herein.

In another exemplary embodiment, a mobile device comprises a housing anda photography module. The photography module is positioned in thehousing and comprises a lens barrel, an optical imaging lens, a modulehousing unit, and an image sensor. The optical image lens is positionedin the lens barrel. The module housing unit is configured to provide aspace where the lens barrel is positioned. The image sensor ispositioned at the image side of the optical imaging lens.

In exemplary embodiments, the module housing unit comprises, but is notlimited to, a lens backseat, which comprises a first lens seat and asecond lens seat, in which the first lens seat is positioned close tothe outside of the lens barrel and along with an axis, the second lensseat is positioned along the axis and around the outside of the firstlens seat, and the lens barrel and the optical imaging lens positionedtherein are driven by the first lens seat to move along the axis.

In exemplary embodiments, the module housing unit further comprises, butis not limited to, an image sensor backseat positioned between the firstlens seat, the second lens seat and the image sensor, and close to thesecond lens seat.

Through controlling the arrangement of the convex or concave shape ofthe surface of the lens element(s) and/or refractive power, the mobiledevice and the optical imaging lens thereof in aforesaid exemplaryembodiments achieve good optical characters and effectively shorten thelengths of the optical imaging lens.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be more readily understood from the followingdetailed description when read in conjunction with the appended drawing,in which:

FIG. 1 is a cross-sectional view of a lens element of one embodiment ofan optical imaging lens according to the present disclosures;

FIG. 2 is a cross-sectional view of a first embodiment of the opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 3 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the first embodiment of the optical imaginglens according to the present disclosures;

FIG. 4 is a table of optical data for each lens element of the opticalimaging lens of the first embodiment of the present disclosures;

FIG. 5 is a table of aspherical data of the first embodiment of theoptical imaging lens according to the present disclosures;

FIG. 6 is a cross-sectional view of a second embodiment of an opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 7 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the second embodiment of the optical imaginglens according to the present disclosures;

FIG. 8 is a table of optical data for each lens element of the opticalimaging lens of the second embodiment of the present disclosures;

FIG. 9 is a table of aspherical data of the second embodiment of theoptical imaging lens according to the present disclosures;

FIG. 10 is a cross-sectional view of a third embodiment of an opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 11 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the third embodiment of the optical imaginglens according the present disclosures;

FIG. 12 is a table of optical data for each lens element of the opticalimaging lens of the third embodiment of the present disclosures;

FIG. 13 is a table of aspherical data of the third embodiment of theoptical imaging lens according to the present disclosures;

FIG. 14 is a cross-sectional view of a fourth embodiment of an opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 15 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the fourth embodiment of the optical imaginglens according the present disclosures;

FIG. 16 is a table of optical data for each lens element of the opticalimaging lens of the fourth embodiment of the present disclosures;

FIG. 17 is a table of aspherical data of the fourth embodiment of theoptical imaging lens according to the present disclosures;

FIG. 18 is a cross-sectional view of a fifth embodiment of an opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 19 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the fifth embodiment of the optical imaginglens according the present disclosures;

FIG. 20 is a table of optical data for each lens element of the opticalimaging lens of the fifth embodiment of the present disclosures;

FIG. 21 is a table of aspherical data of a fifth embodiment of theoptical imaging lens according to the present disclosures;

FIG. 22 is a cross-sectional view of a sixth embodiment of an opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 23 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the sixth embodiment of the optical imaginglens according the present disclosures;

FIG. 24 is a table of optical data for each lens element of the opticalimaging lens of the sixth embodiment of the present disclosures;

FIG. 25 is a table of aspherical data of the sixth embodiment of theoptical imaging lens according to the present disclosures;

FIG. 26 is a cross-sectional view of a seventh embodiment of an opticalimaging lens having six lens elements according to the presentdisclosures;

FIG. 27 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of the seventh embodiment of the optical imaginglens according the present disclosures;

FIG. 28 is a table of optical data for each lens element of the opticalimaging lens of the seventh embodiment of the present disclosures;

FIG. 29 is a table of aspherical data of the seventh embodiment of theoptical imaging lens according to the present disclosures;

FIG. 30 is a table for the values of,

$\frac{EFL}{{CT}\; 3},\frac{TL}{{CT}\; 6},\frac{EFL}{{{CT}\; 2} + {{AC}\; 56}},\frac{{{AC}\; 23} + {{CT}\; 3} + {A\; 34}}{{CT}\; 3},\frac{AAG}{{{AC}\; 23} + {{AC}\; 34}},\frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}},\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}},\frac{ALT}{{CT}\; 6},\frac{EFL}{{{CT}\; 6} + {{AC}\; 56}},\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2},{{and}\mspace{14mu}\frac{TL}{{{CT}\; 2} + {{AC}\; 56}}}$of all seven example embodiments;

FIG. 31 is a structure of an example embodiment of a mobile device; and

FIG. 32 is a partially enlarged view of the structure of another exampleembodiment of a mobile device.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumbers indicate like features. Persons having ordinary skill in the artwill understand other varieties for implementing example embodiments,including those described herein. The drawings are not limited tospecific scale and similar reference numbers are used for representingsimilar elements. As used in the disclosures and the appended claims,the terms “example embodiment,” “exemplary embodiment,” and “presentembodiment” do not necessarily refer to a single embodiment, although itmay, and various example embodiments may be readily combined andinterchanged, without departing from the scope or spirit of the presentinvention. Furthermore, the terminology as used herein is for thepurpose of describing example embodiments only and is not intended to bea limitation of the invention. In this respect, as used herein, the term“in” may include “in” and “on”, and the terms “a”, “an” and “the” mayinclude singular and plural references. Furthermore, as used herein, theterm “by” may also mean “from”, depending on the context. Furthermore,as used herein, the term “if” may also mean “when” or “upon”, dependingon the context. Furthermore, as used herein, the words “and/or” mayrefer to and encompass any and all possible combinations of one or moreof the associated listed items.

As used in the disclosures, the description “a lens element has apositive refractive power (or a negative refractive power)” means aportion of the lens in a vicinity of the optical axis has a positiverefractive power (or a negative refractive power). Furthermore, as usedherein, the description “an object-side (or the image-side) of a lenselement comprises a convex portion (or a concave portion) in a certainregion” means the portion in the certain region parallel to the opticalaxis is more convex outward (or more concave inward) than that in theoutside region close to the certain region in the radial direction. Asshown in FIG. 1, the axis I represents the optical axis and the lenselement is symmetric about the axis I in the radial direction. Theobject-side surface of the lens element comprises a convex portion inthe A region, a concave portion in the B region, and a convex portion inthe C region. The portion in the A region parallel to the optical axisis more convex outward than the portion in the outside region (B region)close to the A region in the radial direction. The portion in the Bregion is more concave inward than the portion in the C region. Theportion in the C region is more convex outward than the E region.Furthermore, as used herein, the description “in a vicinity of aperiphery of a lens element” means in the vicinity of the peripheryregion on the surface of the lens element only where the imaging lightpasses, such as the C region. The imaging light comprises a chief ray Lcand a marginal ray Lm. Furthermore, as used herein, the description “ina vicinity of the optical axis” means in the vicinity of the opticalaxis on the surface of the lens element only where the imaging lightpasses, such as the A region. Besides, the lens element furthercomprises a protruding part E for mounting the lens element in anoptical imaging lens, and ideally, the imaging light will not passthrough the protruding part E. The structure and the shape of theprotruding part E is not limited to this configuration illustrated inthe FIG. 1. To clearly illustrate the structure of each lens element,each portion of the protruding part E in the embodiments is omitted.

Example embodiments of an optical imaging lens may comprise a first lenselement, a second lens element, a third lens element, a fourth lenselement, a fifth lens element, and a sixth lens element, in which eachof the lens elements has an object-side surface facing toward the objectside and an image-side surface facing toward the image side. These lenselements may be arranged sequentially from the object side to the imageside, and example embodiments of the lens as a whole may comprise thesix lens elements having refractive power. In an example embodiment: theobject-side surface of the first lens element comprises a convex portionin a vicinity of the optical axis; the image-side surface of the secondlens element comprises a concave portion in a vicinity of a periphery ofthe second lens element; the image-side surface of the third lenselement comprises a convex portion in a vicinity of a periphery of thethird lens element; the image-side surface of the fourth lens elementcomprises a convex portion in a vicinity of the optical axis; theimage-side surface of the fifth lens element comprises a convex portionin a vicinity of a periphery of the fifth lens element; and theimage-side surface of the sixth lens element comprises a concave portionin a vicinity of the optical axis and a convex portion in a vicinity ofa periphery of the sixth lens element.

The designed characteristics of the lens elements in aforesaid exemplaryembodiments are taken the optical characters and the lengths of theoptical imaging lens into consideration. For example, the first lenselement has a positive refractive power, the object-side surface of thefirst lens element comprises a convex portion in a vicinity of theoptical axis, and the image-side surface of the first lens elementcomprises a convex portion in a vicinity of a periphery of the firstlens element for assisting the optical imaging lens to converge thelight. In conjunction with the above-mention design on the surfaces ofthe lens elements, the image-side surface of the second lens elementcomprises a concave portion in a vicinity of a periphery of the secondlens element, the image-side surface of the third lens element comprisesa convex portion in a vicinity of a periphery of the third lens element,the image-side surface of the fourth lens element comprises a convexportion in a vicinity of the optical axis, the image-side surface of thefifth lens element comprises a convex portion in a vicinity of aperiphery of the fifth lens element, and the image-side surface of thesixth lens element comprises a concave portion in a vicinity of theoptical axis for eliminating the aberration. Further, the object-sidesurface of the second lens element comprises a convex portion in avicinity of the optical axis, a convex portion in a vicinity of aperiphery of the second lens element, and a concave portion between avicinity of the optical axis and a vicinity of a periphery of the secondlens element for improving the efficiency of aberration elimination.Besides, the image-side surface of the sixth lens element comprises aconcave portion in a vicinity of the optical axis and a convex portionin a vicinity of a periphery of the sixth lens element for assisting theoptical imaging lens to correct the field curvature of the opticalimaging lens, reduce the high order aberration of the optical imaginglens, and depress the angle of the chief ray (the incident angle of thelight onto the image sensor), and then the sensitivity of the wholesystem is promoted. Additionally, the object-side surface of the sixthlens element comprises a convex portion in a vicinity of a periphery ofthe sixth lens element for assisting the optical imaging lens toeliminate edge aberration. Therefore, the present embodiment achievesgreat optical performance.

In another exemplary embodiment, the ratio of related parameters of theoptical imaging lens could be controlled to satisfy equations forassisting the designer to design the optical imaging lens with goodoptical characteristics and short total length under practicabletechnic, such as an effective focal length of the optical imaging lens,EFL, and a central thickness of the third lens element along the opticalaxis, CT3, could be controlled to satisfy the equation as follows:

$\begin{matrix}{6.00 \leq {\frac{EFL}{{CT}\; 3}.}} & {{Equation}\mspace{14mu}(1)}\end{matrix}$

In another exemplary embodiment, a distance from the object-side surfaceof the first lens element to the image-side surface of the sixth lenselement, TL, and a central thickness of the sixth lens element along theoptical axis, CT6, could be controlled to satisfy the equation asfollows:

$\begin{matrix}{7.60 \leq {\frac{TL}{{CT}\; 6}.}} & {{Equation}\mspace{14mu}(2)}\end{matrix}$

In another exemplary embodiment, an air gap between the fifth lenselement and the sixth lens element, AC56, a central thickness of thesecond lens element along the optical axis, CT2, and EFL could becontrolled to satisfy the equation as follows:

$\begin{matrix}{5.00 \leq {\frac{EFL}{{{CT}\; 2} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(3)}\end{matrix}$

In another exemplary embodiment, an air gap between the second lenselement and the third lens element, AC23, an air gap between the thirdlens element and the fourth lens element, AC34, and CT3 could becontrolled to satisfy the equation as follows:

$\begin{matrix}{2.30 \leq {\frac{{{AC}\; 23} + {{CT}\; 3} + {{AC}\; 34}}{{CT}\; 3}.}} & {{Equation}\mspace{14mu}(4)}\end{matrix}$

In another exemplary embodiment, a sum of all air gaps from the firstlens element to the sixth lens element along the optical axis, AAG,AC23, and AC34 could be controlled to satisfy the equation as follows:

$\begin{matrix}{\frac{AAG}{{{AC}\; 23} + {{AC}\; 34}} \leq {1.81.}} & {{Equation}\mspace{14mu}(5)}\end{matrix}$

In another exemplary embodiment, an air gap between the first lenselement and the second lens element, AC12, an air gap between the fourthlens element and the fifth lens element, AC45, AC34 and AC56 could becontrolled to satisfy the equation as follows:

$\begin{matrix}{1.20 \leq {\frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(6)}\end{matrix}$

In another exemplary embodiment, a central thickness of the fourth lenselement along the optical axis, CT4, a central thickness of the fifthlens element along the optical axis, CT5, and EFL could be controlled tosatisfy the equation as follows:

$\begin{matrix}{\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}} \leq {5.40.}} & {{Equation}\mspace{14mu}(7)}\end{matrix}$

In another exemplary embodiment, the sum of the thickness of all sixlens elements along the optical axis, ALT, and a central thickness ofthe sixth lens element along the optical axis, CT6, could be controlledto satisfy the equation as follows:

$\begin{matrix}{5.50 \leq {\frac{ALT}{{CT}\; 6}.}} & {{Equation}\mspace{14mu}(8)}\end{matrix}$

In another exemplary embodiment, an air gap between the fifth lenselement and the sixth lens element, AC56, CT6 and EFL could becontrolled to satisfy the equation as follows:

$\begin{matrix}{6.30 \leq {\frac{EFL}{{{CT}\; 6} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(9)}\end{matrix}$

In another exemplary embodiment, a central thickness of the third lenselement, CT3, and EFL could be controlled to satisfy the equation asfollows:

$\begin{matrix}{8.30 \leq {\frac{EFL}{{CT}\; 3}.}} & {{Equation}\mspace{14mu}\left( 1^{\prime} \right)}\end{matrix}$

In another exemplary embodiment, a central thickness of the second lenselement, CT2, a central thickness of the fourth lens element, CT4, and acentral thickness of the fifth lens element, CT5, could be controlled tosatisfy the equation as follows:

$\begin{matrix}{2.80 \leq {\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2}.}} & {{Equation}\mspace{14mu}(10)}\end{matrix}$

In another exemplary embodiment, a central thickness of the second lenselement, CT2, an air gap between the fifth lens element and the sixthlens element, AC56, and TL could be controlled to satisfy the equationas follows:

$\begin{matrix}{5.50 \leq {\frac{TL}{{{CT}\; 2} + {{AC}\; 56}}.}} & {{Equation}\mspace{14mu}(11)}\end{matrix}$

Aforesaid exemplary embodiments are not limited and could be selectivelyincorporated in other embodiments described herein.

Reference is now made to Equation (1). The design for the value of

$\frac{EFL}{{CT}\; 3}$is based on the effective focal length of the optical imaging lens, EFL.The effective focal length of the optical imaging lens, EFL, would beshrunken to meet the demand of small sized optical imaging lens. When

$\frac{EFL}{{CT}\; 3}$meets to Equation (1), the effective focal length of the optical imaginglens, EFL, and the central thickness of the third lens element along theoptical axis, CT3, could be in proper range to prevent excessive centralthickness of the third lens element along the optical axis, CT3, whichis unfavorable for shortening the length of the optical imaging lens. Ifthe value of

$\frac{EFL}{{CT}\; 3}$further satisfy the Equation (1′), the shorten range of the third lenselement along the optical axis, CT3, is greater. More preferably, thevalue of

$\frac{EFL}{{CT}\; 3}$should be further restricted by an upper limit, for example but notlimited to,

$6.00 \leq \frac{EFL}{{CT}\; 3} \leq {15.00.}$

Reference is now made to Equation (2). The design for the value of

$\frac{TL}{{CT}\; 6}$is based on the central thickness of the sixth lens element along theoptical axis, CT6. The central thickness of the sixth lens element alongthe optical axis, CT6, would be shrunken to meet the demand of smallsized optical imaging lens. When

$\frac{TL}{{CT}\; 6}$meets to Equation (2), the central thickness of the sixth lens elementalong the optical axis, CT6, and the distance from the object-sidesurface of the first lens element to the image-side surface of the sixthlens element, TL, could be in proper range to prevent excessive centralthickness of the sixth lens element along the optical axis, CT6, whichis unfavorable for shortening the length of the optical imaging lens.More preferably, the value of

$\frac{TL}{{CT}\; 6}$should be further restricted by an upper limit, for example but notlimited to,

$7.60 \leq \frac{TL}{{CT}\; 6} \leq {13.00.}$

Reference is now made to Equation (3). The design for the value of

$\frac{EFL}{{{CT}\; 2} + {{AC}\; 56}}$is based on the effective focal length of the optical imaging lens, EFL.The effective focal length of the optical imaging lens, EFL, would beshrunken to meet the demand of small sized optical imaging lens. When

$\frac{EFL}{{{CT}\; 2} + {{AC}\; 56}}$meets to Equation (3), the central thickness of the second lens elementalong the optical axis, CT2, and the air gap between the fifth lenselement and the sixth lens element, AC56, could be in proper range toprevent excessive central thickness of the second lens element along theoptical axis, CT2, and excessive air gap between the fifth lens elementand the sixth lens element, AC56, that is unfavorable for shortening thelength of the optical imaging lens. More preferably, the value of

$\frac{EFL}{{{CT}\; 2} + {{AC}\; 56}}$should be further restricted by an upper limit, for example but notlimited to,

$5.00 \leq \frac{EFL}{{{CT}\; 2} + {{AC}\; 56}} \leq {15.00.}$

Reference is now made to Equation (4). The design for the value of

$\frac{{{AC}\; 23} + {{CT}\; 3} + {{AC}\; 34}}{{CT}\; 3}$is based on the path of light, the fabricating yield of each lenselement, and the difficulties of assembling the optical imaging lens.When

$\frac{{{AC}\; 23} + {{CT}\; 3} + {{AC}\; 34}}{{CT}\; 3}$meets to Equation (4), the air gap between the second lens element andthe third lens element, AC23, the air gap between the third lens elementand the fourth lens element, AC34, and the central thickness of thethird lens element along the optical axis, CT3, could be in properarrangement, that is favorable for shortening the length of the opticalimaging lens. More preferably, the value of

$\frac{{{AC}\; 23} + {{CT}\; 3} + {{AC}\; 34}}{{CT}\; 3}$should be further restricted by an upper limit, for example but notlimited to,

$2.30 \leq \frac{{{AC}\; 23} + {{CT}\; 3} + {{AC}\; 34}}{{CT}\; 3} \leq {3.50.}$

Reference is now made to Equation (5). The design for the value of

$\frac{AAG}{{{AC}\; 23} + {{AC}\; 34}}$is based on the air gap between the second lens element and the thirdlens element, AC23. Since the image-side surface of the second lenselement comprises a concave portion in a vicinity of a periphery of thesecond lens element, the emitted light from the second lens element(imaging light) needs enough air gap to incident to a proper position onthe third lens element. Hence, comparing to other air gaps, theshortened range of the air gap between the second lens element and thethird lens element along the optical axis, A23, is under a considerablerestriction. However, too small air gap between the second lens elementand the third lens element along the optical axis, A23, would increasefabrication difficulties of each lens element. When

$\frac{AAG}{{{AC}\; 23} + {{AC}\; 34}}$meets to Equation (5) based on the path of light, and the fabricatingdifficulties of each lens element, the air gaps, AC23, AC34, and AAGcould be in proper arrangement. More preferably, the value of

$\frac{AAG}{{{AC}\; 23} + {{AC}\; 34}}$should be further restricted by an lower limit, for example but notlimited to,

$1.00 \leq \frac{AAG}{{{AC}\; 23} + {{AC}\; 34}} \leq {1.81.}$

Reference is now made to Equation (6). The design for the value of

$\frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}}$is based on each air gap, the path of light, and the difficulties ofassembling the optical imaging lens. When

$\frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}}$meets to Equation (6), each air gap could be in proper arrangement,which is favorable for shortening the length of the optical imaginglens. More preferably, the value of

$\frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}}$should be further restricted by an upper limit, for example but notlimited to,

$1.20 \leq \frac{{{AC}\; 23} + {{AC}\; 34}}{{{AC}\; 12} + {{AC}\; 45} + {{AC}\; 56}} \leq {2.50.}$

Reference is now made to Equation (7). The design for the value of

$\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}}$is based on the effective focal length of the optical imaging lens, EFL.The effective focal length of the optical imaging lens, EFL, would beshrunken to meet the demand of small sized optical imaging lens. When

$\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}}$meets to Equation (7), the central thickness of the fourth lens elementalong the optical axis, CT4, and the central thickness of the fifth lenselement, CT5, would be in a proper range, which is favorable forshortening the length of the optical imaging lens. More preferably, thevalue of

$\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}}$should be further restricted by an lower limit, for example but notlimited to,

$2.50 \leq \frac{EFL}{{{CT}\; 4} + {{CT}\; 5}} \leq {5.40.}$

Reference is now made to Equation (8). The design for the value of

$\frac{ALT}{{CT}\; 6}$is based on the thickness of all six lens elements along the opticalaxis, ALT. The thickness of all six lens elements along the opticalaxis, ALT, would be shrunken to meet the demand of small sized opticalimaging lens. When

$\frac{ALT}{{CT}\; 6}$meets to Equation (8), the central thickness of the sixth lens elementalong the optical axis, CT6, could be in proper range to preventexcessive central thickness of the sixth lens element along the opticalaxis, CT6. More preferably, the value of

$\frac{ALT}{{CT}\; 6}$should be further restricted by an upper limit, for example but notlimited to,

$5.50 \leq \frac{ALT}{{CT}\; 6} \leq {8.50.}$

Reference is now made to Equation (9). The design for the value of

$\frac{EFL}{{{CT}\; 6} + {A\; C\; 56}}$is based on the effective focal length of the optical imaging lens, EFL.The effective focal length of the optical imaging lens, EFL, would beshrunken to meet the demand of small sized optical imaging lens. When

$\frac{EFL}{{{CT}\; 6} + {A\; C\; 56}}$meets to Equation (9), the central thickness of the sixth lens elementalong the optical axis, CT6, and the air gap between the fifth lenselement and the sixth lens element, AC56, could be in proper range toprevent excessive central thickness of the sixth lens element along theoptical axis, CT6, and excessive air gap between the fifth lens elementand the sixth lens element, AC56. More preferably, the value of

$\frac{EFL}{{{CT}\; 6} + {A\; C\; 56}}$should be further restricted by an upper limit, for example but notlimited to,

$6.30 \leq \frac{EFL}{{{CT}\; 6} + {A\; C\; 56}} \leq {9.50.}$

Reference is now made to Equation (10). The design for the value of

$\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2}$is based on the central thickness of the fourth lens element along theoptical axis, CT4, and the central thickness of the fifth lens elementalong the optical axis, CT5. Since the fourth lens element and fifthlens element have larger effective optical diameters, the centralthickness of the fourth lens element along the optical axis, CT4, andthe central thickness of the fifth lens element along the optical axis,CT5, are thicker than the central thickness of the second lens elementalong the optical axis, CT2. When

$\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2}$meets to Equation (10), the central thickness of the second lens elementalong the optical axis, CT2, could be in proper arrangement, which isfavorable for shortening the length of the optical imaging lens. Morepreferably, the value of

$\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2}$should be further restricted by an upper limit, for example but notlimited to,

$2.80 \leq \frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2} \leq {6.50.}$

Reference is now made to Equation (11). The design for the value of

$\frac{TL}{{{CT}\; 2} + {A\; C\; 56}}$is based on the distance between the object-side surface of the firstlens element to the image-side surface of the sixth lens element, TL.The object-side surface of the first lens element to the image-sidesurface of the sixth lens element, TL, would be shrunken to meet thedemand of small sized optical imaging lens. When

$\frac{TL}{{{CT}\; 2} + {A\; C\; 56}}$meets to Equation (11), the central thickness of the second lens elementalong the optical axis, CT2, and the air gap between the fifth lenselement and the sixth lens element, AC56, could be in proper arrangementto prevent excessive second lens element along the optical axis, CT2,and excessive air gap between the fifth lens element and the sixth lenselement, AC56, that is favorable for shortening the length of theoptical imaging lens. More preferably, the value of

$\frac{TL}{{{CT}\; 2} + {A\; C\; 56}}$should be further restricted by an upper limit, for example but notlimited to,

$5.50 \leq \frac{TL}{{{CT}\; 2} + {A\; C\; 56}} \leq {15.00.}$

When implementing example embodiments, more details about the convex orconcave surface structure and/or the refractive power may beincorporated for one specific lens element or broadly for plural lenselements to enhance the control for the system performance and/orresolution, as illustrated in the following embodiments. It is notedthat the details listed here could be incorporated in exampleembodiments if no inconsistency occurs.

Several exemplary embodiments and associated optical data will now beprovided for illustrating example embodiments of optical imaging lenswith good optical characters and a shortened length. Reference is nowmade to FIGS. 2-5. FIG. 2 illustrates a cross-sectional view of a firstembodiment of the optical imaging lens 1 having six lens elementsaccording to the present disclosures. FIGS. 3(a) to 3(d) show examplecharts of longitudinal spherical aberration and other kinds of opticalaberrations of the optical imaging lens 1 according to an exampleembodiment. FIG. 4 illustrates an example table of optical data of eachlens element of the optical imaging lens 1 according to an exampleembodiment. FIG. 5 depicts an example table of aspherical data of theoptical imaging lens 1 according to an example embodiment.

As shown in FIG. 2, the optical imaging lens 1 of the present embodimentcomprises, in order from an object side A1 to an image side A2, anaperture stop 100, a first lens element 110, a second lens element 120,a third lens element 130, a fourth lens element 140, a fifth lenselement 150, and the sixth lens element 160. The aperture stop 100 maybe also disposed between the first lens element 110 and the secondelement 120 or other position. A filtering unit 170 and an image plane180 of an image sensor are positioned at the image side A2 of theoptical image lens 1. More specifically, the filtering unit 170 is an IRcut filter (infrared cut filter) positioned between the sixth lens 160and the image plane 180 of the image sensor. The filtering unit 170selectively absorbs light with specific wavelength from the lightpassing optical imaging lens 1. For example, IR light is absorbed, andthis will prohibit the IR light which is not seen by human eyes fromproducing an image on the image plane 180.

Exemplary embodiments of each lens elements of the optical imaging lens1 will now be described with reference to the drawings. Each of thefirst, second, third, fourth, fifth, and sixth lens elements 110, 120,130, 140, 150, 160 has an object-side surface 111/121/131/141/151/161facing toward the object side A1 and an image-side surface112/122/132/142/152/162 facing toward the image side A2. Bothobject-side surface 111/121/131/141/151/161 and image-side surface112/122/132/142/152/162 may be aspherical surfaces.

The first lens element 110 has a positive refractive power, which may beconstructed by plastic material. The object-side surface 111 is a convexsurface, which comprises a convex portion 111 in a vicinity of theoptical axis. The image-side surface 112 comprises a concave portion1121 in a vicinity of the optical axis, and a convex portion 1122 in avicinity of a periphery of the first lens element 110.

The second lens element 120 may have a negative refractive power, whichmay be constructed by plastic material. The object-side surface 121comprises a convex portion 1211 in a vicinity of the optical axis, aconvex portion 1212 in a vicinity of a periphery of the second lenselement 120, and a concave portion 1213 between a vicinity of theoptical axis and a vicinity of a periphery of the second lens element120. The image-side surface 122 is a concave surface and comprises aconcave portion 1222 in a vicinity of a periphery of the second lenselement 120.

The third lens element 130 may have a positive refractive power, whichmay be constructed by plastic material. The object-side surface 131comprises a convex portion 1311 in a vicinity of the optical axis, and aconcave portion 1312 in a vicinity of a periphery of the third lenselement 130. The image-side surface 132 is a convex surface, whichcomprises a convex portion 1322 in a vicinity of a periphery of thethird lens element 130.

The fourth lens element 140 may have a positive refractive power, whichmay be constructed by plastic material. The object-side surface 141 is aconcave surface. The image-side surface 142 is a convex surface, whichcomprises a concave portion 1421 in a vicinity of the optical axis, anda convex portion 1422 in a vicinity of a periphery of the fourth lenselement 140.

The fifth lens element 150 may have a negative refractive power, whichmay be constructed by plastic material. The object-side surface 151 is aconcave surface. The image-side surface 152 is a convex surface, whichcomprises a convex portion 1522 in a vicinity of a periphery of thefifth lens element 150.

The sixth lens element 160 may have a negative refractive power, whichmay be constructed by plastic material. The object-side surface 161comprises a concave portion 1611 in a vicinity of the optical axis, aconcave portion 1612 in a vicinity of a periphery of the sixth lenselement 160, and a convex portion 1613 between a vicinity of the opticalaxis and a vicinity of a periphery of the sixth lens element 160. Theimage-side surface 162 comprises a concave portion 1621 in a vicinity ofthe optical axis and a convex portion 1622 in a vicinity of a peripheryof the sixth lens element 160.

In example embodiments, air gaps exist between the lens elements110-160, the filtering unit 160, and the image plane 180 of the imagesensor. For example, FIG. 2 illustrates the air gap d₁ existing betweenthe first lens element 110 and the second lens element 120, the air gapd₂ existing between the second lens element 120 and the third lenselement 130, the air gap d₃ existing between the third lens element 130and the fourth lens element 140 the air gap d₄ existing between thefourth lens element 140 and the fifth lens element 150, the air gap d₅existing between the fifth lens element 150 and the sixth lens element160, the air gap d₆ existing between the sixth lens element 160 and thefiltering unit 170, and the air gap d₇ existing between the filteringunit 170 and the image plane 180 of the image sensor. However, in otherembodiments, any of the aforesaid air gaps may or may not exist. Forexample, the profiles of opposite surfaces of any two adjacent lenselements may correspond to each other, and in such situation, the airgaps may not exist. The air gap d₁ is denoted by AC12, the air gap d₂ isdenoted by AC23, the air gaps d₃ is denoted by AC34, the air d₄ gap isdenoted by AC45, the air gap d₅ is denoted by AC56, and the sum of allair gaps d₁, d₂, d₃, d₄, d₅ between the first though sixth lens elementsis denoted by AAG.

FIG. 4 depicts the optical characteristics of each lens elements in theoptical imaging lens 1 and thicknesses of the air gaps of the presentembodiment. The distance from the object-side surface 111 of the firstlens element 110 to the image plane 180 along the optical axis is 5.27mm, and the length of the optical imaging lens 1 is indeed shortened.Besides the image height of the optical imaging lens 1 is 3.185 mm.

The aspherical surfaces, including the object-side surfaces 111, 121,131, 141, 151, 161 and the image-side surfaces 112, 122, 132, 142, 152,162 are all defined by the following aspherical formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}{a_{2i} \times Y^{2i}}}}$

R represents the radius of curvature of the surface of the lens element;

Z represents the depth of the aspherical surface (the perpendiculardistance between the point of the aspherical surface at a distance Yfrom the optical axis and the tangent plane of the vertex on the opticalaxis of the aspherical surface);

Y represents the perpendicular distance between the point of theaspherical surface and the optical axis;

K represents a conic constant; and

a_(2i) represents a aspherical coefficient of 2i^(th) order.

The values of each aspherical parameter, K, and a₄-a₁₆ of each lenselement 110, 120, 130, 140 are represented in FIG. 5.

FIG. 3(a) illustrates the longitudinal spherical aberration of thepresent embodiment, in which curves of different wavelengths aredistributed closely, that means the off-axis light with different heightof different wavelengths converge in a vicinity of the imaging point.FIG. 3(a) shows that the offsets between the off-axis light withdifferent light and the imaging point are controlled to be ±0.035 mm.Therefore, the present embodiment improves the spherical aberration indifferent wavelengths obviously. Additionally, the distances between thethree represented wavelengths are quite close, that means the imagepositions of the different wavelengths converge with one another, suchthat the chromatic aberration is improved obviously.

FIG. 3(b) illustrates an astigmatism aberration in the sagittaldirection of the present embodiment, and FIG. 3(c) illustrates anastigmatism aberration in the tangential direction of the presentembodiment. The focal lengths of the three represented wavelengths inthe whole field of view are within ±0.05 mm, and the focal lengths ofthe sagittal direction are further controlled within ±0.05 mm.Therefore, the optical imaging lens 1 of the present embodiment couldeliminate the aberration effectively. Additionally, the distancesbetween the three represented wavelengths are quite close, that meansthe aberration is improved obviously.

FIG. 3(d) illustrates a distortion aberration of the present embodiment.The distortion aberration of the present embodiment is maintained withinthe range of ±1%, that means the distortion aberration meets the imagequality of optical system. Accordingly, the system length of the opticalimaging lens 1 is shortened to be 5.27 mm approximately, which couldovercome the chromatic aberration and provide better image quality.Therefore, the present embodiment achieves great optical performance andthe length of the optical imaging lens 1 is effectively shortened.

Reference is now made to FIGS. 6-9. FIG. 6 illustrates an examplecross-sectional view of an optical imaging lens 2 having six lenselements of the optical imaging lens according to a second exampleembodiment. FIG. 7 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 2 according to the second example embodiment. FIG. 8 shows anexample table of optical data of each lens element of the opticalimaging lens 2 according to the second example embodiment. FIG. 9 showsan example table of aspherical data of the optical imaging lens 2according to the second example embodiment. The reference numberslabeled in the present embodiment are similar to those in the firstembodiment for the similar elements, but here the reference numbers areinitialed with 2, for example, reference number 231 for labeling theobject-side surface of the third lens element 230, reference number 232for labeling the image-side surface of the third lens element 230, etc.

As shown in FIG. 6, the second embodiment is similar to the firstembodiment. The optical imaging lens 2, in an order from an object sideA1 to an image side A2, comprises an aperture stop 200, first lenselement to sixth lens element 210-260. A filtering unit 270 and an imageplane 280 of an image sensor are positioned at the image side A2 of theoptical imaging lens 2. The arrangement of the convex or concave surfacestructures, including the object-side surfaces 211, 231, 241, 251, 261and image-side surfaces 212, 222, 232, 242, 252, 262, and the refractivepower of the lens elements 210-260 are generally same with the opticalimaging lens 1. The difference between the optical imaging lens 1 andthe optical imaging lens 2 is the radius of curvature, the values of thecentral thicknesses of the lens elements 210-260 and the air gapsbetween the lens elements 210-260 are slight different from the valuesof the optical imaging lens 1. Besides, the second lens element 210 andthe sixth lens element 260 are slight different from these in the firstembodiment. More specifically, the object-side surface 221 of the secondlens element 220 is a convex surface, and the object-side 261 of thesixth lens element 260 is a concave surface.

Please refer to FIG. 8 for the optical characteristics of each lenselements in the optical imaging lens 2 and thicknesses of the air gapsof the present embodiment. The distance from the object-side surface 211of the first lens element 210 to the image plane 280 along the opticalaxis is 5.36 mm, and the length of the optical imaging lens 2 is indeedshortened.

As shown in FIGS. 7(a)-7(d), the optical imaging lens 2 of the presentembodiment shows great characteristics in longitudinal sphericalaberration 7(a), astigmatism in the sagittal direction 7(b), astigmatismin the tangential direction 7(c), and distortion aberration 7(d).Therefore, according to the above illustration, the optical imaging lensof the present embodiment indeed shows great optical performance and thelength of the optical imaging lens 2 is effectively shortened.

Reference is now made to FIGS. 10-13. FIG. 10 illustrates an examplecross-sectional view of an optical imaging lens 3 having six lenselements of the optical imaging lens according to a third exampleembodiment. FIG. 11 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 3 according to the third example embodiment. FIG. 12 shows anexample table of optical data of each lens element of the opticalimaging lens 3 according to the third example embodiment. FIG. 13 showsan example table of aspherical data of the optical imaging lens 3according to the third example embodiment. The reference numbers labeledin the present embodiment are similar to those in the first embodimentfor the similar elements, but here the reference numbers are initialedwith 3, for example, reference number 331 for labeling the object-sidesurface of the third lens element 330, reference number 332 for labelingthe image-side surface of the third lens element 330, etc.

As shown in FIG. 10, the third embodiment is similar to the firstembodiment. The optical imaging lens 3, in an order from an object sideA1 to an image side A2, comprises an aperture stop 300, first lenselement to sixth lens element 310-360. A filtering unit 370 and an imageplane 380 of an image sensor are positioned at the image side A2 of theoptical imaging lens 3. The arrangement of the convex or concave surfacestructures, including the object-side surfaces 311, 341 and image-sidesurfaces 322, 332, 342, 352, 362, and the refractive power of the lenselements 310, 320, 330, 360 are generally same with the optical imaginglens 1. The difference between the optical imaging lens 1 and theoptical imaging lens 3 is the radius of curvature, the values of thecentral thicknesses of the lens elements 310-360 and the air gapsbetween the lens elements 310-360 are slight different from the valuesof the optical imaging lens 1. Besides, the lens elements 310-360 areslight different from these in the first embodiment. More specifically,the image-side surface 312 of the first lens element 310 is a convexsurface, the object-side surface 321 of the second lens element 320comprises a concave portion 3211 in a vicinity of the optical axis and aconvex portion 3212 in a vicinity of a periphery of the second lenselement 320, the object-side surface 331 of the third lens element 330is a concave surface, which comprises a concave portion 3311 in avicinity of the optical axis, the fourth lens element 340 has a negativerefractive power, the fifth lens element 350 has a positive refractivepower, which comprises a convex portion 3511 in a vicinity of theoptical axis and a concave portion 3512 in a vicinity of a periphery ofthe fifth lens element 350, and the object-side surface 361 of the sixthlens element 360 comprises a concave portion 3611 in a vicinity of theoptical axis and a convex portion 3612 in a vicinity of a periphery ofthe sixth lens element 360.

Please refer to FIG. 12 for the optical characteristics of each lenselements in the optical imaging lens 3 and thicknesses of the air gapsof the present embodiment. The distance from the object-side surface 311of the first lens element 310 to the image plane 380 along the opticalaxis is 5.36 mm, and the length of the optical imaging lens 3 is indeedshortened.

As shown in FIGS. 11(a)-11(d), the optical imaging lens 3 of the presentembodiment shows great characteristics in longitudinal sphericalaberration 11(a), astigmatism in the sagittal direction 11(b),astigmatism in the tangential direction 11(c), and distortion aberration11(d). Therefore, according to the above illustration, the opticalimaging lens of the present embodiment indeed shows great opticalperformance and the length of the optical imaging lens 3 is effectivelyshortened.

Reference is now made to FIGS. 14-17. FIG. 14 illustrates an examplecross-sectional view of an optical imaging lens 4 having six lenselements of the optical imaging lens according to a fourth exampleembodiment. FIG. 15 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 4 according to the fourth example embodiment. FIG. 16 shows anexample table of optical data of each lens element of the opticalimaging lens 4 according to the fourth example embodiment. FIG. 17 showsan example table of aspherical data of the optical imaging lens 4according to the fourth example embodiment. The reference numberslabeled in the present embodiment are similar to those in the firstembodiment for the similar elements, but here the reference numbers areinitialed with 4, for example, reference number 431 for labeling theobject-side surface of the third lens element 430, reference number 432for labeling the image-side surface of the third lens element 430, etc.

As shown in FIG. 14, the fourth embodiment is similar to the firstembodiment. The optical imaging lens 4, in an order from an object sideA1 to an image side A2, comprises an aperture stop 400, first lenselement to sixth lens element 410-460. A filtering unit 470 and an imageplane 480 of an image sensor are positioned at the image side A2 of theoptical imaging lens 4. The arrangement of the convex or concave surfacestructures, including the object-side surfaces 411, 451 and image-sidesurfaces 422, 432, 442, 452, 462, and the refractive power of the lenselements 410, 420, 430, 440, 460 are generally same with the opticalimaging lens 1. The difference between the optical imaging lens 1 andthe optical imaging lens 4 is the radius of curvature, the values of thecentral thicknesses of the lens elements 410-460 and the air gapsbetween the lens elements 410-460 are slight different from the valuesof the optical imaging lens 1. Besides, the lens elements 410, 420, 430,450, 460 are slight different from these in the first embodiment. Morespecifically, the image-side surface 412 of the first lens element 410is a convex surface, the object-side surface 421 of the second lenselement 420 is a concave surface, the object-side surface 431 is of thethird lens element 430 is a convex surface, the fifth lens element 450has a positive refractive power, and the object-side surface 461 of thesixth lens element 460 is a concave surface.

Please refer to FIG. 16 for the optical characteristics of each lenselements in the optical imaging lens 4 and thicknesses of the air gapsof the present embodiment. The distance from the object-side surface 411of the first lens element 410 to the image plane 480 along the opticalaxis is 5.36 mm, and the length of the optical imaging lens 4 is indeedshortened.

As shown in FIGS. 15(a)-15(d), the optical imaging lens 4 of the presentembodiment shows great characteristics in longitudinal sphericalaberration 15(a), astigmatism in the sagittal direction 15(b),astigmatism in the tangential direction 15(c), and distortion aberration15(d). Therefore, according to the above illustration, the opticalimaging lens of the present embodiment indeed shows great opticalperformance and the length of the optical imaging lens 4 is effectivelyshortened.

Reference is now made to FIGS. 18-21. FIG. 18 illustrates an examplecross-sectional view of an optical imaging lens 5 having six lenselements of the optical imaging lens according to a fifth exampleembodiment. FIG. 19 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 5 according to the fifth example embodiment. FIG. 20 shows anexample table of optical data of each lens element of the opticalimaging lens 5 according to the fifth example embodiment. FIG. 21 showsan example table of aspherical data of the optical imaging lens 5according to the fifth example embodiment. The reference numbers labeledin the present embodiment are similar to those in the first embodimentfor the similar elements, but here the reference numbers are initialedwith 5, for example, reference number 531 for labeling the object-sidesurface of the third lens element 530, reference number 432 for labelingthe image-side surface of the third lens element 530, etc.

As shown in FIG. 18, the fifth embodiment is similar to the firstembodiment. The optical imaging lens 5, in an order from an object sideA1 to an image side A2, comprises an aperture stop 500, first lenselement to sixth lens element 510-560. A filtering unit 570 and an imageplane 580 of an image sensor are positioned at the image side A2 of theoptical imaging lens 5. The arrangement of the convex or concave surfacestructures, including the object-side surfaces 511, 531, 541, 551 andimage-side surfaces 512, 522, 532, 542, 552, 562, and the refractivepower of the lens elements 510-560 are generally same with the opticalimaging lens 1. The difference between the optical imaging lens 1 andthe optical imaging lens 5 is the radius of curvature, the values of thecentral thicknesses of the lens elements 510-560 and the air gapsbetween the lens elements 510-560 are slight different from the valuesof the optical imaging lens 1. Besides, the lens elements 520, 560 areslight different from these in the first embodiment. More specifically,the object-side surface 521 of the second lens element 520 is a convexsurface, and the object-side surface 561 of the sixth lens element 560is a concave surface.

Please refer to FIG. 20 for the optical characteristics of each lenselements in the optical imaging lens 5 and thicknesses of the air gapsof the present embodiment. The distance from the object-side surface 511of the first lens element 510 to the image plane 580 along the opticalaxis is 5.36 mm, and the length of the optical imaging lens 5 is indeedshortened.

As shown in FIGS. 19(a)-19(d), the optical imaging lens 5 of the presentembodiment shows great characteristics in longitudinal sphericalaberration 19(a), astigmatism in the sagittal direction 19(b),astigmatism in the tangential direction 19(c), and distortion aberration19(d). Therefore, according to the above illustration, the opticalimaging lens of the present embodiment indeed shows great opticalperformance and the length of the optical imaging lens 5 is effectivelyshortened.

Reference is now made to FIGS. 22-25. FIG. 22 illustrates an examplecross-sectional view of an optical imaging lens 6 having six lenselements of the optical imaging lens according to a sixth exampleembodiment. FIG. 23 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 6 according to the sixth example embodiment. FIG. 24 shows anexample table of optical data of each lens element of the opticalimaging lens 6 according to the sixth example embodiment. FIG. 25 showsan example table of aspherical data of the optical imaging lens 6according to the sixth example embodiment. The reference numbers labeledin the present embodiment are similar to those in the first embodimentfor the similar elements, but here the reference numbers are initialedwith 6, for example, reference number 631 for labeling the object-sidesurface of the third lens element 630, reference number 632 for labelingthe image-side surface of the third lens element 630, etc.

As shown in FIG. 22, the sixth embodiment is similar to the firstembodiment. The optical imaging lens 6, in an order from an object sideA1 to an image side A2, comprises an aperture stop 600, first lenselement to sixth lens element 610-660. A filtering unit 670 and an imageplane 680 of an image sensor are positioned at the image side A2 of theoptical imaging lens 6. The arrangement of the convex or concave surfacestructures, including the object-side surfaces 611, 641, 551 andimage-side surfaces 612, 622, 632, 642, 652, 662, and the refractivepower of the lens elements 610-660 are generally same with the opticalimaging lens 1. The difference between the optical imaging lens 1 andthe optical imaging lens 6 is the radius of curvature, the values of thecentral thicknesses of the lens elements 610-660 and the air gapsbetween the lens elements 610-660 are slight different from the valuesof the optical imaging lens 1. Besides, the lens elements 620, 630, 660are slight different from these in the first embodiment. Morespecifically, the object-side surface 621 of the second lens element 620is a convex surface, the object-side surface 631 of the third lenselement 630 is a concave surface, and the object-side surface 661 of thesixth lens element 660 is a concave surface.

Please refer to FIG. 24 for the optical characteristics of each lenselements in the optical imaging lens 6 and thicknesses of the air gapsof the present embodiment. The distance from the object-side surface 611of the first lens element 610 to the image plane 680 along the opticalaxis is 5.21 mm, and the length of the optical imaging lens 6 is indeedshortened.

As shown in FIGS. 23(a)-23(d), the optical imaging lens 6 of the presentembodiment shows great characteristics in longitudinal sphericalaberration 23(a), astigmatism in the sagittal direction 23(b),astigmatism in the tangential direction 23(c), and distortion aberration23(d). Therefore, according to the above illustration, the opticalimaging lens of the present embodiment indeed shows great opticalperformance and the length of the optical imaging lens 6 is effectivelyshortened.

Reference is now made to FIGS. 26-29. FIG. 26 illustrates an examplecross-sectional view of an optical imaging lens 7 having six lenselements of the optical imaging lens according to a seventh exampleembodiment. FIG. 27 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 7 according to the seventh example embodiment. FIG. 28 shows anexample table of optical data of each lens element of the opticalimaging lens 7 according to the seventh example embodiment. FIG. 29shows an example table of aspherical data of the optical imaging lens 7according to the seventh example embodiment. The reference numberslabeled in the present embodiment are similar to those in the firstembodiment for the similar elements, but here the reference numbers areinitialed with 7, for example, reference number 731 for labeling theobject-side surface of the third lens element 730, reference number 732for labeling the image-side surface of the third lens element 730, etc.

As shown in FIG. 26, the seventh embodiment is similar to the firstembodiment. The optical imaging lens 7, in an order from an object sideA1 to an image side A2, comprises an aperture stop 700, first lenselement to sixth lens element 710-760. A filtering unit 770 and an imageplane 780 of an image sensor are positioned at the image side A2 of theoptical imaging lens 7. The arrangement of the convex or concave surfacestructures, including the object-side surfaces 711, 731, 741 andimage-side surfaces 712, 722, 742, 752, 762, and the refractive power ofthe lens elements 710-740, 760 are generally same with the opticalimaging lens 1. The difference between the optical imaging lens 1 andthe optical imaging lens 7 is the radius of curvature, the values of thecentral thicknesses of the lens elements 710-760 and the air gapsbetween the lens elements 710-760 are slight different from the valuesof the optical imaging lens 1. Besides, the lens elements 720, 730, 750,760 are slight different from these in the first embodiment. Morespecifically, the object-side surface 721 of the second lens element 720is a concave surface, the image-side surface 732 of the third lenselement 730 comprises a concave portion 7321 in a vicinity of theoptical axis and a convex portion 7322 in a vicinity of a periphery ofthe third lens element 730, the fifth lens element 750 has a positiverefractive power, which comprises a convex portion 7511 in a vicinity ofthe optical axis, the object-side surface 761 of the sixth lens element760 comprises a convex portion 7611 in a vicinity of the optical axis, aconvex portion 7612 in a vicinity of the a periphery of the sixth lenselement 760, and a concave portion 7613 between a vicinity of theoptical axis and a vicinity of a periphery of the sixth lens element760.

Please refer to FIG. 28 for the optical characteristics of each lenselements in the optical imaging lens 7 and thicknesses of the air gapsof the present embodiment. The distance from the object-side surface 711of the first lens element 710 to the image plane 780 along the opticalaxis is 5.42 mm, and the length of the optical imaging lens 7 is indeedshortened.

As shown in FIGS. 27(a)-27(d), the optical imaging lens 7 of the presentembodiment shows great characteristics in longitudinal sphericalaberration 27(a), astigmatism in the sagittal direction 27(b),astigmatism in the tangential direction 27(c), and distortion aberration27(d). Therefore, according to the above illustration, the opticalimaging lens of the present embodiment indeed shows great opticalperformance and the length of the optical imaging lens 7 is effectivelyshortened.

Please refer to FIG. 30 which shows the values of

$\frac{EFL}{{CT}\; 3},\frac{TL}{{CT}\; 6},\frac{EFL}{{{CT}\; 2} + {A\; C\; 56}},\frac{{A\; C\; 23} + {{CT}\; 3} + {A\; C\; 34}}{{CT}\; 3},\frac{AAG}{{A\; C\; 23} + {A\; C\; 34}},\frac{{A\; C\; 23} + {A\; C\; 34}}{{A\; C\; 12} + {A\; C\; 45} + {A\; C\; 56}},\frac{EFL}{{{CT}\; 4} + {{CT}\; 5}},\frac{ALT}{{CT}\; 6},\frac{EFL}{{{CT}\; 6} + {A\; C\; 56}},\frac{{{CT}\; 4} + {{CT}\; 5}}{{CT}\; 2},{{and}\mspace{14mu}\frac{TL}{{{CT}\; 2} + {A\; C\; 56}}}$of all seven embodiments, and it is clear that the optical imaging lensof the present invention satisfy the Equations (1) and/or (1′), (2),(3), (4), (5), (6), (7), (8), (9), (10) or (11).

Please refer to FIG. 31, which shows an example structural view of afirst embodiment of mobile device 20 applying an aforesaid opticalimaging lens. The mobile device 20 comprises a housing 21 and aphotography module 22 positioned in the housing 21. An example of themobile device 20 may be, but is not limited to, a mobile phone.

As shown in FIG. 31, the photography module 22 may comprise an aforesaidoptical imaging lens, for example the optical imaging lens 1 of thefirst embodiment, a lens barrel 23 for positioning the optical imaginglens 1, a module housing unit 24 for positioning the lens barrel 23, asubstrate 182 for positioning the module housing unit 24, and an imagesensor 181 which is positioned at an image side of the optical imaginglens 1. The image plane 180 is formed on the image sensor 181.

In some other example embodiments, the structure of the filtering unit170 may be omitted. In some example embodiments, the housing 21, thelens barrel 23, and/or the module housing unit 24 may be integrated intoa single component or assembled by multiple components. In some exampleembodiments, the image sensor 181 used in the present embodiment isdirectly attached to a substrate 182 in the form of a chip on board(COB) package, and such package is different from traditional chip scalepackages (CSP) since COB package does not require a cover glass beforethe image sensor 181 in the optical imaging lens 1. Aforesaid exemplaryembodiments are not limited to this package type and could beselectively incorporated in other described embodiments.

The six lens elements 110, 120, 130, 140, 150, 160 are positioned in thelens barrel 23 in the way of separated by an air gap between any twoadjacent lens elements.

The module housing unit 24 comprises a seat element 2401 for positioningthe lens barrel 23 and an image sensor backseat 2406, in which the imagesensor backseat 2406 is not necessary in other embodiment. The lensbarrel 23 and the seat element 2401 are positioned along a same axisI-I′, and the lens barrel 23 is positioned inside the seat element 2401.

Because the length of the optical imaging lens 1 is merely 5.27 (mm),the size of the mobile device 20 may be quite small. Therefore, theembodiments described herein meet the market demand for smaller sizedproduct designs.

Reference is now made to FIG. 32, which shows another structural view ofa second embodiment of mobile device 20′ applying the aforesaid opticalimaging lens 1. One difference between the mobile device 20′ and themobile device 20 may be the seat element 2401 further comprises a firstlens seat 2402, a second lens seat 2403, a coil 2404, and a magneticunit 2405. The first lens seat 2402, which is close to the outside ofthe lens barrel 23, and the lens barrel 23 are positioned along an axisII′. The second lens seat 2403 is positioned along the axis II′ andaround the outside of the first lens seat 2402. The coil 2404 ispositioned between the outside of the first lens seat 2402 and theinside of the second lens seat 2403. The magnetic unit 2405 ispositioned between the outside of the coil 2404 and the inside of thesecond lens seat 2403. The end facing to the image side of the imagesensor backseat 2406 is close to the second lens seat 2403.

The lens barrel 23 and the optical imaging lens 1 positioned therein aredriven by the first lens seat 2402 to move along the axis II′. The reststructure of the mobile device 20′ is similar to the mobile device 20.

Similarly, because the length of the optical imaging lens 5.27 mm, isshortened, the mobile device 20′ may be designed with a smaller size andmeanwhile good optical performance is still provided. Therefore, thepresent embodiment meets the market demand for smaller sized productdesigns, and maintains good optical characteristics and image quality.Accordingly, the present embodiment not only reduces raw material amountof housing for economic benefits, but also meets smaller sized productdesign trend and consumer demand.

According to above illustration, it is clear that the mobile device andthe optical imaging lens thereof in example embodiments, throughcontrolling ratio of at least one central thickness of lens element to asum of all air gaps along the optical axis between six lens elements ina predetermined range, and incorporated with detail structure and/orreflection power of the lens elements, the length of the optical imaginglens is effectively shortened and meanwhile good optical characters arestill provided.

While various embodiments in accordance with the disclosed principleshave been described above, it should be understood that they have beenpresented by way of example only, and are not limiting. Thus, thebreadth and scope of exemplary embodiment(s) should not be limited byany of the above-described embodiments, but should be defined only inaccordance with the claims and their equivalents issuing from thisdisclosure. Furthermore, the above advantages and features are providedin described embodiments, but shall not limit the application of suchissued claims to processes and structures accomplishing any or all ofthe above advantages.

Additionally, the section headings herein are provided for consistencywith the suggestions under 37 C.F.R. 1.77 or otherwise to provideorganizational cues. These headings shall not limit or characterize theinvention(s) set out in any claims that may issue from this disclosure.Specifically, a description of a technology in the “Background” is notto be construed as an admission that technology is prior art to anyinvention(s) in this disclosure. Furthermore, any reference in thisdisclosure to “invention” in the singular should not be used to arguethat there is only a single point of novelty in this disclosure.Multiple inventions may be set forth according to the limitations of themultiple claims issuing from this disclosure, and such claimsaccordingly define the invention(s), and their equivalents, that areprotected thereby. In all instances, the scope of such claims shall beconsidered on their own merits in light of this disclosure, but shouldnot be constrained by the headings herein.

What is claimed is:
 1. An optical imaging lens, disposed sequentiallyfrom an object side to an image side along an optical axis, comprising afirst, a second, a third, a fourth, a fifth, and a sixth lens elements,each of the lens elements having an object-side surface facing towardthe object side and an image-side surface facing toward the image side,wherein: the image-side surface of the first lens element comprises aconcave portion in a vicinity of the optical axis; the third lenselement has a positive refractive power; the fourth lens element has apositive refractive power; the object-side surface of the fifth lenselement comprises a concave portion in a vicinity of a periphery of thefifth lens element; the image-side surface of the fifth lens elementcomprises a convex portion in a vicinity of the optical axis; theimage-side surface of the sixth lens element comprises a concave portionin a vicinity of the optical axis; and the optical imaging lens as awhole has only the six lens elements having refractive power.
 2. Theoptical imaging lens of claim 1, wherein an effective focal length ofthe optical imaging lens is EFL, a central thickness of the fourth lenselement along the optical axis is CT4, a central thickness of the fifthlens element along the optical axis is CT5, and EFL, CT4, and CT5satisfy the equation:EFL/(CT4+CT5)≤5.40.
 3. The optical imaging lens of claim 1, wherein asum of all air gaps from the first lens element to the sixth lenselement along the optical axis is AAG, an air gap between the fourthlens element and the fifth lens element is AC45, a central thickness ofthe sixth lens element along the optical axis is CT6, and AAG, AC45 andCT6 satisfy the equation:1.58≤AAG/(AC45+CT6)≤2.14.
 4. The optical imaging lens of claim 1,wherein a sum of thicknesses of all six lens elements along the opticalaxis is ALT, an air gap between the first lens element and the secondlens element is AC12, an air gap between the second lens element and thethird lens element is AC23, and ALT, AC12, and AC23 satisfy theequation:5.03≤ALT/(AC12+AC23)≤5.85.
 5. The optical imaging lens of claim 1,wherein a distance from the object-side surface of the first lenselement to the image-side surface of the sixth lens element is TL, acentral thickness of the second lens element along the optical axis isCT2, an air gap between the fifth lens element and the sixth lenselement is AC56, and TL, CT2, and AC56 satisfy the equation:5.50≤TL/(CT2+AC56).
 6. The optical imaging lens of claim 1, wherein acentral thickness of the first lens element along the optical axis isCT1, a central thickness of the second lens element along the opticalaxis is CT2, a central thickness of the fourth lens element along theoptical axis is CT4, and CT1, CT2, and CT4 satisfy the equation:3.39≤(CT1+CT4)/CT2≤6.57.
 7. The optical imaging lens of claim 1, whereina central thickness of the second lens element along the optical axis isCT2, a central thickness of the third lens element along the opticalaxis is CT3, a central thickness of the fourth lens element along theoptical axis is CT4, a central thickness of the fifth lens element alongthe optical axis is CT5, and CT2, CT3, CT4, and CT5 satisfy theequation:0.82≤(CT4+CT5)/(CT2+CT3)≤2.51.
 8. The optical imaging lens of claim 1,wherein an effective focal length of the optical imaging lens is EFL, acentral thickness of the third lens element along the optical axis isCT3, and EFL and CT3 satisfy the equation:6.00≤EFL/CT3.
 9. The optical imaging lens of claim 1, wherein a sum ofall air gaps from the first lens element to the sixth lens element alongthe optical axis is AAG, an air gap between the second lens element andthe third lens element is AC23, an air gap between the fourth lenselement and the fifth lens element is AC45, and AAG, AC23, and AC45satisfy the equation:1.53≤AAG/(AC23+AC45)≤2.99.
 10. The optical imaging lens of claim 1,wherein the image-side surface of the second lens element comprises aconcave portion in a vicinity of the optical axis.
 11. The opticalimaging lens of claim 1, wherein the image-side surface of the sixthlens element comprises a convex portion in a vicinity of a periphery ofthe sixth lens element.
 12. The optical imaging lens of claim 1, whereinan effective focal length of the optical imaging lens is EFL, a sum ofall air gaps from the first lens element to the sixth lens element alongthe optical axis is AAG, and EFL and AAG satisfy the equation:3.19≤EFL/AAG≤4.35.
 13. The optical imaging lens of claim 1, wherein adistance from the object-side surface of the first lens element to theimage-side surface of the sixth lens element is TL, an air gap betweenthe second lens element and the third lens element is AC23, an air gapbetween the third lens element and the fourth lens element is AC34, andTL, AC23, and AC34 satisfy the equation:5.90≤TL/(AC23+AC34)≤7.63.
 14. The optical imaging lens of claim 1,wherein a central thickness of the third lens element is CT3, a centralthickness of the fourth lens element is CT4, wherein CT3 and CT4 satisfythe equation:0.59≤CT4/CT3≤2.74.
 15. The optical imaging lens of claim 1, wherein acentral thickness of the fourth lens element is CT4, an air gap betweenthe second lens element and the third lens element is AC23, an air gapbetween the fifth lens element and the sixth lens element is AC56, andCT4, AC23, and AC56 satisfy the equation:0.41≤CT4/(AC23+AC56)≤1.39.
 16. The optical imaging lens of claim 1,wherein a central thickness of the first lens element along the opticalaxis is CT1, a central thickness of the second lens element along theoptical axis is CT2, a central thickness of the third lens element alongthe optical axis is CT3, and CT1, CT2, and CT3 satisfy the equation:1.46≤(CT1+CT2)/CT3≤2.99
 17. The optical imaging lens of claim 1, whereinan effective focal length of the optical imaging lens is EFL, a centralthickness of the second lens element along the optical axis is CT2, acentral thickness of the third lens element along the optical axis isCT3, and EFL, CT2, and CT3 satisfy the equation:4.29≤EFL/(CT2+CT3)≤7.63.
 18. The optical imaging lens of claim 1,wherein an air gap between the third lens element and the fourth lenselement is AC34, a central thickness of the third lens element along theoptical axis is CT3, a central thickness of the fourth lens element isCT4, and AC34, CT3, and CT4 satisfy the equation:0.93≤(AC34+CT4)/CT3≤3.27
 19. The optical imaging lens of claim 1,wherein a distance from the object-side surface of the first lenselement to the image-side surface of the sixth lens element is TL, acentral thickness of the first lens element along the optical axis isCT1, an air gap between the first lens element and the second lenselement is AC12, and TL, CT1, and AC12 satisfy the equation:4.22≤TL/(CT1+AC12)≤5.94.
 20. The optical imaging lens of claim 1,wherein a sum of all air gaps from the first lens element to the sixthlens element along the optical axis is AAG, a central thickness of thefifth lens element along the optical axis is CT5, and AAG and CT5satisfy the equation:1.57≤AAG/CT5≤3.27.